Oakland Mills Bridge
The two spans when lighted by LED at night
Photo taken by Jason Smith in August 2011
BH Photo #212825
The Oakland Mills Bridge is a long-span combination through and pony truss with seven steel stringers approaches and one Pratt pony approach span on the east end of the structures. Spanning the Skunk River south of Oakland Mills, the 358-foot bridge features pinned connections throughout and is supported by a stone and timber substructure. The bridge's history may be traced to the summer of 1876, when county officials advertised for bids for the construction project. The Missouri Valley Bridge and Iron Company of Leavenworth, Kansas, was ultimately awarded the construction contract with prices set at $15.25 per lineal foot and $7.90 per cubic yard for masonry work. The approximate cost of the bridge therefore amounted to close to $12,000. Using steel components rolled by the Pennsylvania firm Phoenix Iron Company, the bridge was completed by MVB&I under the supervision of county engineer John Schreiner. Although closed to vehicular traffic today, the Oakland Mills Bridge is a popular spot for picnickers in Oakland Mills State Park, where the bridge retains a high degree of structural integrity.
In the early 1880s, the pin-connected Pratt truss superseded the bowstring arch-truss as the iron bridge of choice for medium-span wagon crossings. Patented in 1844 by Thomas and Caleb Pratt, the Pratt design is distinguished by vertical members acting in compression and diagonals that act in tension. Virtually all of the major regional bridge fabricators manufactured Pratt trusses and marketed them extensively to Iowa's counties. This included the Missouri Valley Bridge and Iron Company. Thousands of pinned Pratt trusses were erected throughout Iowa, in both through and pony configurations, and many remain in service today. The Oakland Mills Bridge is distinguished as one of the earliest Pratt through trusses remaining in the state. It is an outstanding multiple-span example of this mainstay structural type [adapted from Crow-Dolby and Fraser 1992].
- Pratt through truss bridge over Skunk River on Pedestrian trail (formerly county road) at Oakland Mills State Park
- Oakland Mills, Henry County, Iowa
- Open to pedestrians
- Built in 1876; converted to pedestrian bridge in the 1970s and became part of the state park
- - Missouri Valley Bridge & Iron Co. of Leavenworth, Kansas
- The Oakland Mills Bridge consists of the following spans from north to south: 1 span three panel Pratt half-hip pony truss, multiple span wooden trestle, two span Pratt through truss (each with 7 panels) and one four panel (V-shaped) Pratt pony truss. All are pin-connected.
Posted to the National Register of Historic Places
- Approximate latitude, longitude
- +40.93549, -91.61696 (decimal degrees)
40°56'08" N, 91°37'01" W (degrees°minutes'seconds")
- Approximate UTM coordinates
- 15/616430/4532517 (zone/easting/northing)
- Quadrangle map:
- Mount Pleasant
- Inventory numbers
- NRHP 98000525 (National Register of Historic Places reference number)
BH 49512 (Bridgehunter.com ID)
- November 18, 2013: Updated by Luke Harden: Added category "Park"
- August 29, 2013: New Street View added by Dave King
- March 30, 2013: New photos from Chris Gonnerman
- September 6, 2011: Added by Jason Smith